如何在JMeter中捕获SignalR连接字符串？ConnectionData参数配置异常

Let's break down your problems and solve them one by one:

1. Resolving the connectionData Parameter Formatting Problem #

Your connectionData is a JSON array: [{"name":"alertshub"},{"name":"loggerhub"},{"name":"notificationhub"}] — the issue here is that raw JSON can't be directly passed in a URL because special characters (like quotes, brackets) aren't URL-safe. Here's how to handle it in JMeter:

• Option 1: Pre-encode the JSON manually
  Convert your JSON string to URL-encoded format. For your example, the encoded version would be:

  %5B%7B%22name%22%3A%22alertshub%22%7D%2C%7B%22name%22%3A%22loggerhub%22%7D%2C%7B%22name%22%3A%22notificationhub%22%7D%5D
  

  You can paste this directly into your URL in place of ${connectionData}.

• Option 2: Use JMeter's built-in __urlencode function (recommended)
  This is more maintainable, especially if your connectionData might change later:

  1. Add a User Defined Variables element to your test plan, and set a variable like:

     connectionData_raw = [{"name":"alertshub"},{"name":"loggerhub"},{"name":"notificationhub"}]
     

  2. In your SignalR connect URL, replace ${connectionData} with:

     ${__urlencode(${connectionData_raw})}
     

  JMeter will automatically encode the JSON into a URL-safe string when the request runs.

2. Capturing SignalR Connection Tokens (and Related Strings) in JMeter #

SignalR uses a negotiate request to establish initial connection details. Here's how to capture the required parameters:

Step 1: Send the Negotiate Request #

Add an HTTP Request element to your test plan, configured to hit your SignalR negotiate endpoint. For your setup, this would be:

• Method: GET
• Path: /Web/signalr/negotiate

Step 2: Extract connectionToken (and other values) with a JSON Extractor #

Add a JSON Extractor as a child of the negotiate HTTP Request, with these settings:

• Reference Name: connectionToken
• JSON Path Expression: $.ConnectionToken (note: case sensitivity matters — check your negotiate response's JSON structure to confirm the exact key name)
• Match No.: 1 (to grab the first match)

If you need to extract other values from the negotiate response (like connectionId), just add additional JSON Extractors with the appropriate JSON Path expressions.

Step 3: Verify the Captured Values #

Add a Debug Sampler to your test plan and run a quick test. Check the View Results Tree to confirm that connectionToken (and any other variables you're using) are being captured correctly before using them in your connect request.

A few extra tips:

• Make sure the clientProtocol value in your connect URL matches what your SignalR server expects (you're using 1.5 which is common for older SignalR versions).
• If you're using a different transport (like WebSockets), the URL structure might vary slightly, but the negotiate and parameter extraction process stays similar.

内容的提问来源于stack exchange，提问作者Lakshmikanth